LAUSR

Introduction: High-power short-duration (HPSD) ablation via the St. Jude EnSite™ Velocity™ system (St. Paul, MN) utilizes 50W delivered for up to 15s, guided by a Lesion Size Index of 5-6 specific to the Velocity™ system. HPSD is a novel way to use a contact force-sensing catheter optimized for power-controlled radiofrequency ablation of atrial fibrillation (AF). Procedural and clinical outcomes of HPSD compared to standard-power standard-duration (SPSD; 20-25W until 400-500 gram seconds, up to 60s) and temperature-controlled non-contact (TCNC; 20-40W up to 60s of ablation) settings would inform this strategy. Methods: We studied consecutive cases of patients with paroxysmal or persistent AF undergoing pulmonary vein isolation (PVI) with TCNC, SPSD, and HPSD between 7/1/13 to 11/1/19. Procedural data collected include total radiofrequency time (RFT), time to isolate the left pulmonary veins (LPVT), time to isolate the right pulmonary veins (RPVT), and safety outcomes. Clinical data collected include sinus rhythm maintenance 3 and 12-months post-procedure. Results: A total of 171 patients were studied (44 TCNC, 51 SPSD, 76 HPSD). There was no difference in age, sex, or AF type between groups. RFT was shorter when comparing HPSD to SPSD (71 vs 101 min; p<0.01), HPSD to TCNC (71 vs 146 min; p<0.01), and SPSD to TCNC groups (101 vs 146 min; p<0.01). This was driven by decreases in LPVT between the HPSD vs SPSD (34 vs 46 min; p=0.04), HPSD vs TCNC (34 vs 72 min; p<0.01), and SPSD vs TCNC groups (46 vs 72 min; p<0.01), as well as decreases in RPVT between the HPSD vs SPSD (42 vs 54 min; p=0.03), HPSD vs TCNC (42 vs 75 min; p<0.01), and SPSD vs TCNC groups (54 vs 75 min; p<0.01). There was no difference in sinus rhythm maintenance after 3 or 12-months between groups overall, and when stratified by AF type, left atrial volume, CHA 2 DS 2 -VASc score, or left ventricular EF. There was a numerical difference in safety with no adverse events in HPSD (0/76 in HPSD vs 1/51 in SPSD vs 3/44 in TCNC; p=0.06). Conclusion: AF ablation with contact force utilizing an HPSD ablation strategy reduced procedure times with similar sinus rhythm maintenance compared to SPSD and TCNC approaches. Further research is needed to determine whether clinical outcomes differ with a larger population and longer follow-up.